, the world's largest online retailer, suffered a major outage today. In a brief statement the company said its engineers were working to fix the issue – which lasted for nearly two hours – but provided no reason as to why the outage occurred. During the outage, attempts to access the site were met with only the following message: “Http/1.1 Service Unavailable.”

While outages in major online properties are rare these days, Amazon has experienced them before, including a five hour hit in 2004 and a two hour failure in August 2006. It’s hard to know exactly how much this will cost them in lost sales, though simple math pegs it at about $29,000 a minute based on the retailer's 2007 net revenue of $14.835 billion.

Of course, these calculations are by no means to be taken as accurate, seeing that customers can easily come back after the downtime to make their purchases. Nonetheless it's still perplexing how a giant online retailer such as Amazon could be unavailable for so long.